Method and apparatus for detecting fast motion scenes

Abstract

A video indexing method and device for selecting keyframes from each detected scene in the video. The method and device detects fast motion scenes by counting the number of consecutive scene changes detected.

What is claimed is:  
     
       1. A system for detecting frames of fast motion scenes, comprising: 
       a receiver which receives source video having frames;  
       a comparator which detects video cuts between two frames; and  
       a fast motion detector for detecting video cuts occurring after each frame of at least three consecutive frames of video, which indicates a fast motion scene rather than true video cuts.  
     
     
       2. A system as claimed in  claim 1 , further including a counter for counting the number of consecutive frames having video cuts detected thereafter. 
     
     
       3. A system as claimed in  claim 2 , further including a keyframe extractor for extracting a single key frame from the number of frames. 
     
     
       4. A system as claimed in  claim 1 , wherein the comparator includes a device for comparing the DCT coefficients of the frames to determine if a video cut has occurred between the two frames. 
     
     
       5. A method for detecting frames of fast motion scenes, comprising: 
       receiving source video having frames;  
       comparing the frames of video with each other to detect video cuts between the frames; and  
       detecting fast motion by detecting at least three consecutive frames having video cuts detected after each frame indicating a fast motion scene rather than true video cuts.  
     
     
       6. The method as claimed in  claim 5 , further including the steps of counting the number of consecutive frames having video cuts detected thereafter. 
     
     
       7. The method as claimed in  claim 6 , further including the step of extracting a single key frame from the number of frames. 
     
     
       8. The method as claimed in  claim 5 , wherein the step of comparing compares the DCT coefficients of the frame and detects if a significant change occurred between the DCT coefficients of two frames. 
     
     
       9. An indexing system, comprising: 
       a receiver which receives source video having frames;  
       a fast motion detector which identifies a group of frames of video belonging to a fast motion scene, by detecting at least three consecutive video cuts which indicates a fast motion scene rather than true video cuts; and  
       a selector which receives from the fast motion detector an indication of which group of frames belong to the fast motion scene; and  
       which selects at least one key frame for an index from the group of frames.  
     
     
       10. The indexing system as claimed in  claim 9 , wherein the fast motion detector uses optical flow computation. 
     
     
       11. The indexing system as claimed in  claim 9 , wherein the fast motion detector uses an affine motion model. 
     
     
       12. The indexing system as claimed in  claim 9 , wherein the fast motion detector uses motion estimation based on edges. 
     
     
       13. The indexing system as claimed in  claim 9 , wherein the fast motion detector uses motion estimation based on rigid body motion. 
     
     
       14. The indexing system as claimed in  claim 9 , wherein the fast motion detector uses motion estimation based on the number of intra coded blocks in P and B frames in MPEG.